The built environment is a subject of great importance at COP26, and the scale and importance of the climate crisis and of the business’ responsibility to deal with it come under scrutiny. A recent report from the UN’s Global Alliance for Buildings and Construction demonstrates that the buildings and construction sector accounts for 38% of global CO2 emissions.
Increasing heed has been paid recently to emissions resulting from how buildings are managed: the manner of which they are heated, cooled and illuminated. However, the production and supply of building materials and the construction of buildings have gotten less heed. And they produce 10% of global emissions.
A great area within the sector survives on a cycle of demolition and new construction. In the UK, approximately 50,000 buildings are torn down each year. So is building greener the solution?
In spite of efforts by sustainable architecture pioneer William McDonough and organisations including World Green Building Council, disrupting this demolition and new-build cycle has proven tough.
Reusing standing building stock, if not accomplished sustainably, can spike emissions. But reuse is not the automatic alternative.
Many architects opt for glamorous new buildings, not sustainable design methods and retrofits, and money could be made by tearing down and replacing buildings. Money is the matter: in the UK, VAT rates promote new builds and penalise renovations.
One idea is to have additional economic incentives for those who sell building materials, conduct demolitions or whose business model highlights new builds, as opposed to dealing with standing buildings, refurbishing them and intermingling them into new schemes – to not do things a different way.
In architecture education and professional accreditation, climate literacy has been lacking. This has left architects unable to deal with the climate crisis.
Yet times are changing. Architects Climate Action Network and Architects Declare, launched in 2019, are two organisations intended to elevate awareness in the construction business of the climate crisis, decarbonise the sector and drive the shift toward renewable and green building. And Architects’ Journal initiated the RetroFirst campaign in 2019, which encourages prioritising retrofitting over demolition and new construction. As the latter campaign emphasises, the greenest buildings are those that already stand.
In September, a report published by the Royal Academy of Engineering drew further heed to the environmental expenses that the business incurs and possible ways to resolve them. Central to this new concept is what architects and developers deem a whole-life carbon approach.
The whole-life theory takes into account a building’s entire life cycle, from building, occupation and renovation to repair, demolition and disposal. In a standard UK housing block, emissions from building and maintenance make up 51% of the building’s total carbon emissions.
Rendering buildings energy efficient to operate has been a long-term priority. But in most places, government policies for low or zero-carbon buildings still do not take into account the thusly called hidden or embodied emissions. These result from the extraction and creation of building materials, like cement, and the building process. Green-building certification plans do not include them.
Substantial carbon savings could be attained through adaptable construction processes.
Yet even buildings with a shorter lifespan can be rendered more sustainable via a whole-life carbon approach.
Wood and bio-based materials join sustainable principles in the concept of “cradle-to-cradle” production and manufacturing, which promotes recycling.
Milan has been promoted as a symbol of sustainability strategies, and is set to be Italy’s initial zero-emissions social housing site. This project involves building with minimal soil excavation and bio-sourced building materials with bountiful greenery and little space for cars. Internal heating systems will be empowered by renewable energy sources.
The issue is that even L’Innesto will be fully carbon-neutral three decades following its building. The project depends on carbon offsetting to achieve zero-carbon credentials.
When French architects Anne Lacaton and Jean-Philippe Vassal won the Pritzker Prize this year, the win was regarded as a turning point. They have garnered a reputation for turning down commissions or supplying proof to city councils why refurbishment would be preferable and less expensive than constructing something new.
Yet building greener mostly involves actual building.
Green projects like L’Innesto would represent a major step forward. But the fight against climate change promises to be tough—which means that, for the interim, we must be conscientious about what we build.
Image source: istockphoto.com